- Tytuł:
- Comparative Study of the Electronic Structures of $Fe_3O_4$ and $Fe_2SiO_4$
- Autorzy:
-
Piekarz, P.
Oleś, A.
Parlinski, K. - Powiązania:
- https://bibliotekanauki.pl/articles/1536886.pdf
- Data publikacji:
- 2010-08
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
71.27.+a
71.30.+h
71.38.-k - Opis:
- The electronic properties of two spinels $Fe_3O_4$ and $Fe_2SiO_4$ are studied by the density functional theory. The local Coulomb repulsion U and the Hund exchange J between the 3d electrons on iron are included. For U = 0, both spinels are half-metals, with the minority $t_{2g}$ states at the Fermi level. Magnetite remains a metal in a cubic phase even at large values of U. The metal-insulator transition is induced by the $X_3$ phonon, which lowers the total energy and stabilizes the charge-orbital ordering. $Fe_2SiO_4$ transforms to a Mott insulating state for U > 2 eV with a gap $Δ_g$ ~ U. The antiferromagnetic interactions induce the tetragonal distortion, which releases the geometrical frustration and stabilizes the long-range order. The differences of electronic structures in the high-symmetry cubic phases and the distorted low-symmetry phases of both spinels are discussed.
- Źródło:
-
Acta Physica Polonica A; 2010, 118, 2; 307-312
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł